We turn now to the developing head line late today about actor robin Williams, his wife releasing a statement thanking everyone for the out pouring of good wishes, she added something else revealing robin Williams received a Parkinson's diagnosis and wasn't ready to reveal it to the world. Nick watt. Reporter: Tonight, we are learning about one more struggle faced by the irrepressible robin Williams in the months before he died. Robin's sobriety was intact his wife Susan said in a written statement. He was brave as he struggled with his own battles of depression, anxiety, as well as early stages of Parkinson's disease, which he was not yet ready to share publicly. Early Parkinson's consists of tremor, a little bit of slowness, and perhaps postural changes so people lean forward. Reporter: Around 1.5 million Americans have Parkinson's, research suggests, a link between the disease and clinical depression. Michael J. Fox a long time friend of Williams, who was diagnosed with Parkinson's in 1991, just tweeted, stunned to learn robin had pd. Pretty sure his support for our foundation predated his diagnosis. A true friend, I wish him peace. Williams' family have requested privacy since his death, are all sharing their memories of the man most of us thought we knew, but only knew on screen. His youngest son Cody saying, I will miss him and take him with me everywhere I go for the rest of my life. And will look forward forever to the moment when I get to see him again. Susan, his wife, hopes others might live learning a lesson from how he died. It is our hope, in the wake of robin's tragic passing, she said, that others will find the strength to seek the care and support they need to treat whatever battles, they are facing, so they may feel less afraid. Williams' widow says the family found solace in the tremendous outpouring of affection and admiration since his death. His greatest legacy aside from his three kids, the joy and happiness he brought, particularly to those fighting personal battles. David. All right. Nick watt, thank you. To ABC's Dr. Jen Ashton, it must have been painful for the family to reveal this. Once you heard this, you thought there could be a link here with the Parkinson's and the depression. It's an overwhelming diagnosis for anyone. But there is a link. We know major depression occurs in about 20 to 40% of patients with Parkinson's. Dealing with them separately is difficult enough, when you combine them? Very difficult to treat depression in a patient with Parkinson's, but there is excellent treatment now. And there is reason for hope. Reason for hope. Dr. Ashton, thank you.

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